Staging and Grading Discussion of Borderline Cases in Gray Zones.

Introduction: Staging and grading for chronic periodontal disease, as described in 2018, is designed to focus on key distinctions with the recognition that there is a subset of individuals who are on a different clinical trajectory of disease. The staging and grading framework aids the clinician in generating a periodontal diagnosis, however, some cases fall into gray zones in which the simple diagnostic parameters make it challenging to categorize the patient. These cases do not present with clear clinical findings and medical and dental histories that fit within the simple guidelines defined in the staging and grading tables and subsequent algorithms.

Case Presentation: Two cases are presented and demonstrate typical clinical scenarios that fall into gray zones when it comes to differentiating whether the patient will respond predictably to standard principles of care. Case 1 presents a scenario in which the patient's early history suggests the potential for disease progression and increases the likelihood that the patient may develop a need for complex rehabilitation due to periodontal breakdown. Clinical judgment was used to evaluate whether the patient remained at elevated risk and the potential implications for disease progression. Case 1 was diagnosed with generalized Stage III, Grade B. The initial presentation of Case 2 had a higher severity and complexity and therefore was diagnosed with generalized Stage IV, Grade C. The need for complex rehabilitation in Case 2, however, was not primarily due to periodontitis.

Conclusion: Decision guidelines and algorithms help in establishing a standardized diagnosis, however cases that fall into gray zones require clinical judgment to establish the most appropriate diagnosis to guide a treatment plan that is personalized based on current knowledge.